Benjamin e



To all whom it may concern:

. action the mother-liquor containing the impualumina with water, or atthe time of so doing,

' 35 Baum, or thereabout,at the boiling-point) that it will partially solidify on cooling, formin bags, and subject the same to'pressure in a .with or without exhaustion, and so obtain heat until it is sufliciently strong'to give a My inventiourelates to the purification of sulphate of alumina by forming of the impure "UNITED STATES llulllul PATEN OFFICE.

BENJAMIN E. R. NEWLANDs-OF TEMPLE noose, EAST HAM, oouNTYou ESSEX, ENGLAND.

MANUFACTURE or su LPHATE OF ALUMINA.

' SPECIFICATION forming part of Letters Patent No. 243,949, dated July 5, 1881.

Application filed February 10, 1881. (No specimens.) Patented in England December 17, 1880.

Be it known thatI, BENJAMIN EDWARD REINA NEWLANDS, a subject of the Queen of Great Britain, and residing at Temple House, East Ham, county of Essex, England, have invented certain Improvements in the Mannfacture of Sulphate ot"Alumina,-(lor which I have obtained a patent in Great Britain, No. 5,287, dated December l7, l880,) of which the following is a specification. 1

salt a magma containing suflicient' water to hold the impurities 'in soTfl'tTon and'l'eave "the sulphate of alumina in a practical! y pure state, and then removing by pressure or centrifugal rities in solution. In carrying out my invention, I evaporate a solution of sulphate of alumina, containing more or less impurities, to such a degree (say ing a magma or mass of cr5sta l's,-or 'I add a small quantity of water to solid sulphate of alumina and incorporate the two together so as to produce a magma. This magma I place hydraulic or other press, or I submit it to pressure in a filter-press worked by hydraulic or other power, or I place it in an apparatus in which it is exposed to'atmospheric pressure cakes of sulphate of aluminacontaining almost no free acid and onlya very small amount of iron. Instead of using a press, the magma may be dried in a'centrifugal machine lined, by preference, with flannel, and thus a nearly pure salt may be obtained. ,After havingseparated a considerable portion of the sulphate of alumina by the means hereinbefore described the residual mother-liquor is concentrated by magma of crystals on cooling, and this second magma is submitted to pressure, as before, and yields a tolerably pure sulphate of alumina. The same operation may be repeated, and the impure mother-liquor finallyleft yields a sul" phate of alumina containing a considerable amount of iron, which may be used for the purification of sewage or for any other purpose for which sulphate of alumiuais required, and

in which ,the presenceot' iron is not objection.

able.

In carrying my invention into etfect, instead of using ordinary sulphate of alumina, I some- I sometimes add' to it asmall quantity of hydrochloric acid or of a soluble chloride, such chloride of aluminium, capable of forming chloride of iron by double decomposition with the sulphate of iron present. This addition renders the iron more easily removable.

I claim as my invention The method of purifying sulphate of alumina from-sulphuric acid and iron by evaporating a solution of the impure salt to'the proper de gree, or by adding water to said salt in s'nflicient quantity to'obtain the impurities in so lution and leave the sulphate of alumina practically pure, and then separating the motherliqnor containing the impurities by pressure or centrifugal action, substantially as described. In testimony whereofl have signed myname to thtsspeeification in the presence of two subscribing witnesses. B. E. R. NEWLANDS.

Witnesses:

- H. S. CARR, 82 Graham Road, Dalston, Clerk.

G. I. MARSHALL,

2 Portlmul Villas, Barking Road, Essex, Clerk. 

